Jeff McLane and Zach Berman

He just walked off? No celebratory hugs with his teammates? No handshake for his defeated opponents? Dirk Nowitzki, as the clock ticked down on his career-defining moment, just left?

I was more stunned by Nowitzki’s reaction to winning last night than I was by the Mavericks dusting the Heat in six games, but it made sense when I heard his post-game interview: Nowitzki told ESPN the emotions were so great, he wanted to get out of the spotlight. He was overcome.

That, I could understand. A championship in the NBA cements a star’s legacy; a failure puts a hole in it. Before he won a title Sunday night, there were plenty of arguments for Nowitzki as an NBA great, but his critics would always have the “yes but …” argument that you can never entirely refute: “Yes, but, he never won it all.”

In one stellar postseason, Nowitzki forever erased the “yes, but” argument. The qualities of greatness - talent, production, leadership, longevity and, finally, achievement - are now all on the resume.

"Dirk Nowitzki is one of the greatest players in the history of this game," Mavericks coach Rick Carlisle said after the game. "That has been validated tonight."

Nowitzki had to know he didn’t have many more opportunities for that validation. Which is why he made me think of Andy Reid (actually, he made me first think of Donovan McNabb, but with the quarterback elsewhere, let’s not pick that fight today).

Poll

As a Philadelphia fan, did you actually root for a Dallas team (the Mavs) for the first time?

Yes.

No.

The Eagles coach has the production that reflects talent – a .609 winning percentage, longest tenured coach in the NFL, consistent playoff appearances – but sports arguments about greatness seem now to always hinge on one topic: championships.

It might be just me, but my sense is that in the not-too-distant past, titles were a significant measure, but not the only one. Players like Barry Sanders and Tony Gwynn got immense acclaim, even though neither lifted a trophy. Of course there are different measuring sticks for running backs and outfielders versus basketball stars and quarterbacks, who have far more ability to influence games. (Dan Marino, for one, is a player of the same era who was criticized for never winning the big one).

But where I remember championships becoming THE measure was in the Michael Jordan era. By willing himself to six titles, he so clearly separated himself from contemporaries like Karl Malone, Charles Barkley and Patrick Ewing that it became the argument to end all arguments, in all sports.

I’m reminded of this every time I see one of those ubiquitous ads for “Bad Teacher,” the one where a teacher is arguing with a kid over Jordan versus LeBron James. The teacher brings up Jordan’s six rings and bellows, “that’s the only argument I need, Shawn!”

(SI’s Joe Posnanski has a nice take on the clip in last week’s issue).

When it comes to Reid, you can always count on a vocal segment of Eagles fans to make the argument in reverse. Reid backers point to his winning record and the Eagles struggles before he arrived. His critics point to an empty trophy case and growl, "that’s the only argument I need."

Even Reid seems to feel it: he needs a championship to complete the work he started here. It took Nowitzki 13 seasons to get his title. Reid will be in his 13th year as Eagles head coach in 2011. He, like Nowitzki, has to know that opportunities are starting to run short.

People around the Eagles described Reid as more emotional than usual last season. Nowitzki would understand. You only get so many chances to do away with the “yes, but …” argument.